The RACEPAC 4 has 4 litres of capacity and a one-size construction with side adjustment. It is the simplest option when mandatory kit, food and hydration can be kept small.
The RACEPAC 8 increases capacity to 8 litres and uses a sized wrap-around construction. Its expandable rear compartment provides more room for clothing, food and mandatory kit while retaining accessible front storage.
The RACEPAC 20 is substantially different at the rear. Its 20 litre capacity is combined with waterproof main storage, a waterproof top pocket, external mesh and rear/side pockets, and bungee compression to help control a larger or changing load. It is the option to consider when considerably more kit or greater self-sufficiency is required.